Skip to main content
Top
Published in: Respiratory Research 1/2019

Open Access 01-12-2019 | Review

Exhaled particles and small airways

Authors: B. Bake, P. Larsson, G. Ljungkvist, E. Ljungström, A-C Olin

Published in: Respiratory Research | Issue 1/2019

Login to get access

Abstract

Background

Originally, studies on exhaled droplets explored properties of airborne transmission of infectious diseases. More recently, the interest focuses on properties of exhaled droplets as biomarkers, enabled by the development of technical equipment and methods for chemical analysis. Because exhaled droplets contain nonvolatile substances, particles is the physical designation. This review aims to outline the development in the area of exhaled particles, particularly regarding biomarkers and the connection with small airways, i e airways with an internal diameter < 2 mm.

Main body

Generation mechanisms, sites of origin, number concentrations of exhaled particles and the content of nonvolatile substances are studied. Exhaled particles range in diameter from 0.01 and 1000 μm depending on generation mechanism and site of origin. Airway reopening is one scientifically substantiated particle generation mechanism. During deep expirations, small airways close and the reopening process produces minute particles. When exhaled, these particles have a diameter of < 4 μm. A size discriminating sampling of particles < 4 μm and determination of the size distribution, allows exhaled particle mass to be estimated. The median mass is represented by particles in the size range of 0.7 to 1.0 μm. Half an hour of repeated deep expirations result in samples in the order of nanogram to microgram. The source of these samples is the respiratory tract ling fluid of small airways and consists of lipids and proteins, similarly to surfactant. Early clinical studies of e g chronic obstructive pulmonary disease and asthma, reported altered particle formation and particle composition.

Conclusion

The physical properties and content of exhaled particles generated by the airway reopening mechanism offers an exciting noninvasive way to obtain samples from the respiratory tract lining fluid of small airways. The biomarker potential is only at the beginning to be explored.
Appendix
Available only for authorised users
Literature
1.
go back to reference Horvath I, Barnes PJ, Loukides S, Sterk PJ, Hogman M, Olin AC, Amann A, Antus B, Baraldi E, Bikov A, et al. A European Respiratory Society technical standard: exhaled biomarkers in lung disease. Eur Respir J. 2017;49. Horvath I, Barnes PJ, Loukides S, Sterk PJ, Hogman M, Olin AC, Amann A, Antus B, Baraldi E, Bikov A, et al. A European Respiratory Society technical standard: exhaled biomarkers in lung disease. Eur Respir J. 2017;49.
2.
go back to reference Pecchiari M, Santus P, Radovanovic D, D'Angelo E. Acute effects of long-acting bronchodilators on small airways detected in COPD patients by single-breath N2 test and lung P-V curve. J Appl Physiol (1985). 2017;123:1266–75.CrossRef Pecchiari M, Santus P, Radovanovic D, D'Angelo E. Acute effects of long-acting bronchodilators on small airways detected in COPD patients by single-breath N2 test and lung P-V curve. J Appl Physiol (1985). 2017;123:1266–75.CrossRef
3.
go back to reference Santus P, Radovanovic D, Mascetti S, Pauletti A, Valenti V, Mantero M, Papi A, Contoli M. Effects of bronchodilation on biomarkers of peripheral airway inflammation in COPD. Pharmacol Res. 2018;133:160–9.CrossRef Santus P, Radovanovic D, Mascetti S, Pauletti A, Valenti V, Mantero M, Papi A, Contoli M. Effects of bronchodilation on biomarkers of peripheral airway inflammation in COPD. Pharmacol Res. 2018;133:160–9.CrossRef
4.
go back to reference Konstantinidi EM, Lappas AS, Tzortzi AS, Behrakis PK. Exhaled breath condensate: technical and diagnostic aspects. ScientificWorldJournal. 2015;2015:435160.CrossRef Konstantinidi EM, Lappas AS, Tzortzi AS, Behrakis PK. Exhaled breath condensate: technical and diagnostic aspects. ScientificWorldJournal. 2015;2015:435160.CrossRef
5.
go back to reference Olofson JBB, Bergman B, Ullman A, Svärdsudd K. Prediction of COPD and related events improvs by combining spirometry and the single breath nitrogen test. COPD: J Chron Obstruct Pulmon Dis. 2018 In press. Olofson JBB, Bergman B, Ullman A, Svärdsudd K. Prediction of COPD and related events improvs by combining spirometry and the single breath nitrogen test. COPD: J Chron Obstruct Pulmon Dis. 2018 In press.
6.
go back to reference Verbanck S. Physiological measurement of the small airways. Respiration. 2012;84:177–88.CrossRef Verbanck S. Physiological measurement of the small airways. Respiration. 2012;84:177–88.CrossRef
7.
go back to reference Almstrand AC, Josefson M, Bredberg A, Lausmaa J, Sjovall P, Larsson P, Olin AC. TOF-SIMS analysis of exhaled particles from patients with asthma and healthy controls. Eur Respir J. 2012;39:59–66.CrossRef Almstrand AC, Josefson M, Bredberg A, Lausmaa J, Sjovall P, Larsson P, Olin AC. TOF-SIMS analysis of exhaled particles from patients with asthma and healthy controls. Eur Respir J. 2012;39:59–66.CrossRef
8.
go back to reference Almstrand AC, Ljungstrom E, Lausmaa J, Bake B, Sjovall P, Olin AC. Airway monitoring by collection and mass spectrometric analysis of exhaled particles. Anal Chem. 2009;81:662–8.CrossRef Almstrand AC, Ljungstrom E, Lausmaa J, Bake B, Sjovall P, Olin AC. Airway monitoring by collection and mass spectrometric analysis of exhaled particles. Anal Chem. 2009;81:662–8.CrossRef
9.
go back to reference Bredberg A, Gobom J, Almstrand AC, Larsson P, Blennow K, Olin AC, Mirgorodskaya E. Exhaled endogenous particles contain lung proteins. Clin Chem. 2012;58:431–40.CrossRef Bredberg A, Gobom J, Almstrand AC, Larsson P, Blennow K, Olin AC, Mirgorodskaya E. Exhaled endogenous particles contain lung proteins. Clin Chem. 2012;58:431–40.CrossRef
10.
go back to reference Larsson P, Bake B, Wallin A, Hammar O, Almstrand AC, Larstad M, Ljungstrom E, Mirgorodskaya E, Olin AC. The effect of exhalation flow on endogenous particle emission and phospholipid composition. Respir Physiol Neurobiol. 2017;243:39–46.CrossRef Larsson P, Bake B, Wallin A, Hammar O, Almstrand AC, Larstad M, Ljungstrom E, Mirgorodskaya E, Olin AC. The effect of exhalation flow on endogenous particle emission and phospholipid composition. Respir Physiol Neurobiol. 2017;243:39–46.CrossRef
11.
go back to reference Ostling J, Van Geest M, Viklund E, Mirgorodskaya E, Olin A-C. Exploring particles from exhaled air as a new source for protein biomarkers from the airways. Eur Respir J 2017;50:Suppl 61, OA321. Ostling J, Van Geest M, Viklund E, Mirgorodskaya E, Olin A-C. Exploring particles from exhaled air as a new source for protein biomarkers from the airways. Eur Respir J 2017;50:Suppl 61, OA321.
12.
go back to reference Duguid JP. The numbers and the sites of origin of the droplets expelled during expiratory activities. Edinb Med J. 1945;52:385–401.PubMedPubMedCentral Duguid JP. The numbers and the sites of origin of the droplets expelled during expiratory activities. Edinb Med J. 1945;52:385–401.PubMedPubMedCentral
13.
go back to reference Loudon RG, Roberts RM. Droplet expulsion from the respiratory tract. Am Rev Respir Dis. 1967;95:435–42.PubMed Loudon RG, Roberts RM. Droplet expulsion from the respiratory tract. Am Rev Respir Dis. 1967;95:435–42.PubMed
14.
go back to reference Papineni RS, Rosenthal FS. The size distribution of droplets in the exhaled breath of healthy human subjects. J Aerosol Med. 1997;10:105–16.CrossRef Papineni RS, Rosenthal FS. The size distribution of droplets in the exhaled breath of healthy human subjects. J Aerosol Med. 1997;10:105–16.CrossRef
15.
go back to reference Edwards DA, Man JC, Brand P, Katstra JP, Sommerer K, Stone HA, Nardell E, Scheuch G. Inhaling to mitigate exhaled bioaerosols. Proc Natl Acad Sci U S A. 2004;101:17383–8.CrossRef Edwards DA, Man JC, Brand P, Katstra JP, Sommerer K, Stone HA, Nardell E, Scheuch G. Inhaling to mitigate exhaled bioaerosols. Proc Natl Acad Sci U S A. 2004;101:17383–8.CrossRef
16.
go back to reference Bake B, Ljungstrom E, Claesson A, Carlsen HK, Holm M, Olin AC. Exhaled particles after a standardized breathing maneuver. J Aerosol Med Pulm Drug Deliv. 2017;30:267–73.CrossRef Bake B, Ljungstrom E, Claesson A, Carlsen HK, Holm M, Olin AC. Exhaled particles after a standardized breathing maneuver. J Aerosol Med Pulm Drug Deliv. 2017;30:267–73.CrossRef
17.
go back to reference Chao CYH, Wan MP, Morawska L, Johnson GR, Ristovski ZD, Hargreaves ZD, Mengersen K, Corbett S, Lif Y, Xie X, Katoshevski D. Characterization of expiration air jets and droplet size distributions immediately at the mouth opening. J Aerosol Sci. 2009;40:122–33. Chao CYH, Wan MP, Morawska L, Johnson GR, Ristovski ZD, Hargreaves ZD, Mengersen K, Corbett S, Lif Y, Xie X, Katoshevski D. Characterization of expiration air jets and droplet size distributions immediately at the mouth opening. J Aerosol Sci. 2009;40:122–33.
18.
go back to reference Haslbeck K, Schwarz K, Hohlfeld JM, Seume JR, Koch W. Submicron droplet formation in the human lung. J Aerosol Sci. 2010;41:429–38.CrossRef Haslbeck K, Schwarz K, Hohlfeld JM, Seume JR, Koch W. Submicron droplet formation in the human lung. J Aerosol Sci. 2010;41:429–38.CrossRef
19.
go back to reference Holmgren H, Ljungstrom E. Influence of film dimensions on film droplet formation. J Aerosol Med Pulm Drug Deliv. 2012;25:47–53.CrossRef Holmgren H, Ljungstrom E. Influence of film dimensions on film droplet formation. J Aerosol Med Pulm Drug Deliv. 2012;25:47–53.CrossRef
20.
go back to reference Watanabe W, Thomas M, Clarke R, Klibanov AM, Langer R, Katstra J, Fuller GG, Griel LC, Fiegel J, Edwards D. Why inhaling salt water changes what we exhale. J Colloid Interface Sci. 2007;307:71–8.CrossRef Watanabe W, Thomas M, Clarke R, Klibanov AM, Langer R, Katstra J, Fuller GG, Griel LC, Fiegel J, Edwards D. Why inhaling salt water changes what we exhale. J Colloid Interface Sci. 2007;307:71–8.CrossRef
21.
go back to reference Morawska LJGR, Ristowski ZD, Hargreaves M, Mengersen K, Corbett S, Chao CYH, Li Y, Katoshevski D. Size distribution and sites of origin of droplets expelled from the human respiratory tract during expiratory activities. Aerosol Science. 2009;40:256–69.CrossRef Morawska LJGR, Ristowski ZD, Hargreaves M, Mengersen K, Corbett S, Chao CYH, Li Y, Katoshevski D. Size distribution and sites of origin of droplets expelled from the human respiratory tract during expiratory activities. Aerosol Science. 2009;40:256–69.CrossRef
22.
go back to reference Almstrand AC, Bake B, Ljungstrom E, Larsson P, Bredberg A, Mirgorodskaya E, Olin AC. Effect of airway opening on production of exhaled particles. J Appl Physiol (1985). 2010;108:584–8.CrossRef Almstrand AC, Bake B, Ljungstrom E, Larsson P, Bredberg A, Mirgorodskaya E, Olin AC. Effect of airway opening on production of exhaled particles. J Appl Physiol (1985). 2010;108:584–8.CrossRef
23.
go back to reference Johnson GR, Morawska L. The mechanism of breath aerosol formation. J Aerosol Med Pulm Drug Deliv. 2009;22:229–37.CrossRef Johnson GR, Morawska L. The mechanism of breath aerosol formation. J Aerosol Med Pulm Drug Deliv. 2009;22:229–37.CrossRef
24.
go back to reference Fabian P, Brain J, Houseman EA, Gern J, Milton DK. Origin of exhaled breath particles from healthy and human rhinovirus-infected subjects. J Aerosol Med Pulm Drug Deliv. 2011;24:137–47.CrossRef Fabian P, Brain J, Houseman EA, Gern J, Milton DK. Origin of exhaled breath particles from healthy and human rhinovirus-infected subjects. J Aerosol Med Pulm Drug Deliv. 2011;24:137–47.CrossRef
25.
go back to reference Dollfuss RE, Milic-Emili T, Bates DV. Regional ventilation of the lung studied with boluses of 133 xenon. Resp Physiol. 1967;2. Dollfuss RE, Milic-Emili T, Bates DV. Regional ventilation of the lung studied with boluses of 133 xenon. Resp Physiol. 1967;2.
26.
go back to reference Milic-Emili J, Henderson JA, Dolovich MB, Trop D, Kaneko K. Regional distribution of inspired gas in the lung. J Appl Physiol. 1966;21:749–59.CrossRef Milic-Emili J, Henderson JA, Dolovich MB, Trop D, Kaneko K. Regional distribution of inspired gas in the lung. J Appl Physiol. 1966;21:749–59.CrossRef
27.
go back to reference Sutherland PW, Katsura T, Milic-Emili J. Previous volume history of the lung and regional distribution of gas. J Appl Physiol. 1968;25:566–74.CrossRef Sutherland PW, Katsura T, Milic-Emili J. Previous volume history of the lung and regional distribution of gas. J Appl Physiol. 1968;25:566–74.CrossRef
28.
go back to reference Burger EJ Jr, Macklem P. Airway closure: demonstration by breathing 100 percent O2 at low lung volumes and by N2 washout. J Appl Physiol. 1968;25:139–48.CrossRef Burger EJ Jr, Macklem P. Airway closure: demonstration by breathing 100 percent O2 at low lung volumes and by N2 washout. J Appl Physiol. 1968;25:139–48.CrossRef
29.
go back to reference Engel LA, Grassino A, Anthonisen NR. Demonstration of airway closure in man. J Appl Physiol. 1975;38:1117–25.CrossRef Engel LA, Grassino A, Anthonisen NR. Demonstration of airway closure in man. J Appl Physiol. 1975;38:1117–25.CrossRef
30.
go back to reference Anthonisen NR, Danson J, Robertson PC, Ross WR. Airway closure as a function of age. Respir Physiol. 1969;8:58–65.CrossRef Anthonisen NR, Danson J, Robertson PC, Ross WR. Airway closure as a function of age. Respir Physiol. 1969;8:58–65.CrossRef
31.
go back to reference Hughes JM, Rosenzweig DY, Kivitz PB. Site of airway closure in excised dog lungs: histologic demonstration. J Appl Physiol. 1970;29:340–4.CrossRef Hughes JM, Rosenzweig DY, Kivitz PB. Site of airway closure in excised dog lungs: histologic demonstration. J Appl Physiol. 1970;29:340–4.CrossRef
32.
go back to reference Pecchiari M, Radovanovic D, Santus P, D'Angelo E. Airway occlusion assessed by single breath N2 test and lung P-V curve in healthy subjects and COPD patients. Respir Physiol Neurobiol. 2016;234:60–8.CrossRef Pecchiari M, Radovanovic D, Santus P, D'Angelo E. Airway occlusion assessed by single breath N2 test and lung P-V curve in healthy subjects and COPD patients. Respir Physiol Neurobiol. 2016;234:60–8.CrossRef
33.
go back to reference Milic-Emili J, Torchio R, D'Angelo E. Closing volume: a reappraisal (1967-2007). Eur J Appl Physiol. 2007;99:567–83.CrossRef Milic-Emili J, Torchio R, D'Angelo E. Closing volume: a reappraisal (1967-2007). Eur J Appl Physiol. 2007;99:567–83.CrossRef
34.
go back to reference Holmgren H, Bake B, Olin AC, Ljungstrom E. Relation between humidity and size of exhaled particles. J Aerosol Med Pulm Drug Deliv. 2011;24:253–60.CrossRef Holmgren H, Bake B, Olin AC, Ljungstrom E. Relation between humidity and size of exhaled particles. J Aerosol Med Pulm Drug Deliv. 2011;24:253–60.CrossRef
35.
go back to reference Schwarz K, Biller H, Windt H, Koch W, Hohlfeld JM. Characterization of exhaled particles from the healthy human lung--a systematic analysis in relation to pulmonary function variables. J Aerosol Med Pulm Drug Deliv. 2010;23:371–9.CrossRef Schwarz K, Biller H, Windt H, Koch W, Hohlfeld JM. Characterization of exhaled particles from the healthy human lung--a systematic analysis in relation to pulmonary function variables. J Aerosol Med Pulm Drug Deliv. 2010;23:371–9.CrossRef
36.
go back to reference Holmgren H, Ljungström E, Almstrand A-C, Bake B, Olin A-C. Size Distribution of Exhaled Particles in the Range from 0.01 to 2.0 μm; 2010. Holmgren H, Ljungström E, Almstrand A-C, Bake B, Olin A-C. Size Distribution of Exhaled Particles in the Range from 0.01 to 2.0 μm; 2010.
37.
go back to reference Johnson GR, Morawskaa L, Ristovski ZD, Hargreaves M, Mengersen K, Chao CYH, Wan MP, Li Y, Xie X, Katoshevski D, Corbett S. Modality of human expired aerosol size distributions. J Aerosol Science. 2011;42:839–51.CrossRef Johnson GR, Morawskaa L, Ristovski ZD, Hargreaves M, Mengersen K, Chao CYH, Wan MP, Li Y, Xie X, Katoshevski D, Corbett S. Modality of human expired aerosol size distributions. J Aerosol Science. 2011;42:839–51.CrossRef
38.
go back to reference Holmgren H, Gerth E, Ljungstrom E, Larsson P, Almstrand AC, Bake B, Olin AC. Effects of breath holding at low and high lung volumes on amount of exhaled particles. Respir Physiol Neurobiol. 2013;185:228–34.CrossRef Holmgren H, Gerth E, Ljungstrom E, Larsson P, Almstrand AC, Bake B, Olin AC. Effects of breath holding at low and high lung volumes on amount of exhaled particles. Respir Physiol Neurobiol. 2013;185:228–34.CrossRef
39.
go back to reference Schwarz K, Biller H, Windt H, Koch W, Hohlfeld JM. Characterization of exhaled particles from the human lungs in airway obstruction. J Aerosol Med Pulm Drug Deliv. 2015;28:52–8.CrossRef Schwarz K, Biller H, Windt H, Koch W, Hohlfeld JM. Characterization of exhaled particles from the human lungs in airway obstruction. J Aerosol Med Pulm Drug Deliv. 2015;28:52–8.CrossRef
40.
go back to reference Larsson P, Mirgorodskaya E, Samuelsson L, Bake B, Almstrand AC, Bredberg A, Olin AC. Surfactant protein a and albumin in particles in exhaled air. Respir Med. 2012;106:197–204.CrossRef Larsson P, Mirgorodskaya E, Samuelsson L, Bake B, Almstrand AC, Bredberg A, Olin AC. Surfactant protein a and albumin in particles in exhaled air. Respir Med. 2012;106:197–204.CrossRef
41.
go back to reference Larsson P, Larstad M, Bake B, Hammar O, Bredberg A, Almstrand AC, Mirgorodskaya E, Olin AC. Exhaled particles as markers of small airway inflammation in subjects with asthma. Clin Physiol Funct Imaging. 2017;37:489–97. Larsson P, Larstad M, Bake B, Hammar O, Bredberg A, Almstrand AC, Mirgorodskaya E, Olin AC. Exhaled particles as markers of small airway inflammation in subjects with asthma. Clin Physiol Funct Imaging. 2017;37:489–97.
42.
go back to reference Beck O, Sandqvist S, Eriksen P, Franck J, Palmskog G. Method for determination of methadone in exhaled breath collected from subjects undergoing methadone maintenance treatment. J Chromatogr B Analyt Technol Biomed Life Sci. 2010;878:2255–9.CrossRef Beck O, Sandqvist S, Eriksen P, Franck J, Palmskog G. Method for determination of methadone in exhaled breath collected from subjects undergoing methadone maintenance treatment. J Chromatogr B Analyt Technol Biomed Life Sci. 2010;878:2255–9.CrossRef
43.
go back to reference Beck O, Sandqvist S, Franck J. Demonstration that methadone is being present in the exhaled breath aerosol fraction. J Pharm Biomed Anal. 2011;56:1024–8.CrossRef Beck O, Sandqvist S, Franck J. Demonstration that methadone is being present in the exhaled breath aerosol fraction. J Pharm Biomed Anal. 2011;56:1024–8.CrossRef
44.
go back to reference Ljungkvist Göran US, Åsa T, Karina S, Björn B, Per L, Ann-Charlotte A, Emilia V, Oscar H, Sören S, Olof B, Anna-Carin O. Two techniques to sample non-volatiles in breath – exemplified by methadone. J Breath Res. 2017; In press. Ljungkvist Göran US, Åsa T, Karina S, Björn B, Per L, Ann-Charlotte A, Emilia V, Oscar H, Sören S, Olof B, Anna-Carin O. Two techniques to sample non-volatiles in breath – exemplified by methadone. J Breath Res. 2017; In press.
45.
go back to reference Larstad M, Almstrand AC, Larsson P, Bake B, Larsson S, Ljungstrom E, Mirgorodskaya E, Olin AC. Surfactant protein a in exhaled endogenous particles is decreased in chronic obstructive pulmonary disease (COPD) patients: a pilot study. PLoS One. 2015;10:e0144463.CrossRef Larstad M, Almstrand AC, Larsson P, Bake B, Larsson S, Ljungstrom E, Mirgorodskaya E, Olin AC. Surfactant protein a in exhaled endogenous particles is decreased in chronic obstructive pulmonary disease (COPD) patients: a pilot study. PLoS One. 2015;10:e0144463.CrossRef
46.
go back to reference McDonough JE, Yuan R, Suzuki M, Seyednejad N, Elliott WM, Sanchez PG, Wright AC, Gefter WB, Litzky L, Coxson HO, et al. Small-airway obstruction and emphysema in chronic obstructive pulmonary disease. N Engl J Med. 2011;365:1567–75.CrossRef McDonough JE, Yuan R, Suzuki M, Seyednejad N, Elliott WM, Sanchez PG, Wright AC, Gefter WB, Litzky L, Coxson HO, et al. Small-airway obstruction and emphysema in chronic obstructive pulmonary disease. N Engl J Med. 2011;365:1567–75.CrossRef
47.
go back to reference Nathan N, Taytard J, Duquesnoy P, Thouvenin G, Corvol H, Amselem S, Clement A. Surfactant protein a: a key player in lung homeostasis. Int J Biochem Cell Biol. 2016;81:151–5.CrossRef Nathan N, Taytard J, Duquesnoy P, Thouvenin G, Corvol H, Amselem S, Clement A. Surfactant protein a: a key player in lung homeostasis. Int J Biochem Cell Biol. 2016;81:151–5.CrossRef
48.
49.
go back to reference Hogg JC, Macklem PT, Thurlbeck WM. Site and nature of airway obstruction in chronic obstructive lung disease. N Engl J Med. 1968;278:1355–60.CrossRef Hogg JC, Macklem PT, Thurlbeck WM. Site and nature of airway obstruction in chronic obstructive lung disease. N Engl J Med. 1968;278:1355–60.CrossRef
50.
go back to reference Hogg JC, Chu F, Utokaparch S, Woods R, Elliott WM, Buzatu L, Cherniack RM, Rogers RM, Sciurba FC, Coxson HO, Pare PD. The nature of small-airway obstruction in chronic obstructive pulmonary disease. N Engl J Med. 2004;350:2645–53.CrossRef Hogg JC, Chu F, Utokaparch S, Woods R, Elliott WM, Buzatu L, Cherniack RM, Rogers RM, Sciurba FC, Coxson HO, Pare PD. The nature of small-airway obstruction in chronic obstructive pulmonary disease. N Engl J Med. 2004;350:2645–53.CrossRef
51.
go back to reference Hogg JC, Pare PD, Hackett TL. The contribution of small airway obstruction to the pathogenesis of chronic obstructive pulmonary disease. Physiol Rev. 2017;97:529–52.CrossRef Hogg JC, Pare PD, Hackett TL. The contribution of small airway obstruction to the pathogenesis of chronic obstructive pulmonary disease. Physiol Rev. 2017;97:529–52.CrossRef
52.
go back to reference Ericson PA, Mirgorodskaya E, Hammar OS, Viklund EA, Almstrand AR, Larsson PJ, Riise GC, Olin AC. Low levels of exhaled surfactant protein a associated with BOS after lung transplantation. Transplant Direct. 2016;2:e103.CrossRef Ericson PA, Mirgorodskaya E, Hammar OS, Viklund EA, Almstrand AR, Larsson PJ, Riise GC, Olin AC. Low levels of exhaled surfactant protein a associated with BOS after lung transplantation. Transplant Direct. 2016;2:e103.CrossRef
53.
go back to reference Bredberg A, Josefson M, Almstrand AC, Lausmaa J, Sjovall P, Levinsson A, Larsson P, Olin AC. Comparison of exhaled endogenous particles from smokers and non-smokers using multivariate analysis. Respiration. 2013;86:135–42.CrossRef Bredberg A, Josefson M, Almstrand AC, Lausmaa J, Sjovall P, Levinsson A, Larsson P, Olin AC. Comparison of exhaled endogenous particles from smokers and non-smokers using multivariate analysis. Respiration. 2013;86:135–42.CrossRef
Metadata
Title
Exhaled particles and small airways
Authors
B. Bake
P. Larsson
G. Ljungkvist
E. Ljungström
A-C Olin
Publication date
01-12-2019
Publisher
BioMed Central
Published in
Respiratory Research / Issue 1/2019
Electronic ISSN: 1465-993X
DOI
https://doi.org/10.1186/s12931-019-0970-9

Other articles of this Issue 1/2019

Respiratory Research 1/2019 Go to the issue
Live Webinar | 27-06-2024 | 18:00 (CEST)

Keynote webinar | Spotlight on medication adherence

Live: Thursday 27th June 2024, 18:00-19:30 (CEST)

WHO estimates that half of all patients worldwide are non-adherent to their prescribed medication. The consequences of poor adherence can be catastrophic, on both the individual and population level.

Join our expert panel to discover why you need to understand the drivers of non-adherence in your patients, and how you can optimize medication adherence in your clinics to drastically improve patient outcomes.

Prof. Kevin Dolgin
Prof. Florian Limbourg
Prof. Anoop Chauhan
Developed by: Springer Medicine
Obesity Clinical Trial Summary

At a glance: The STEP trials

A round-up of the STEP phase 3 clinical trials evaluating semaglutide for weight loss in people with overweight or obesity.

Developed by: Springer Medicine